The ear is an inertial navigation Vestibular disorders ... dizziness 2016.pdf · Causes of...
Transcript of The ear is an inertial navigation Vestibular disorders ... dizziness 2016.pdf · Causes of...
Otologic 4/27/2016
Timothy C. Hain, M.D. 1
Vestibular disordersRecognition and Medical
Management
Timothy C. Hain, MD
Chicago Dizziness and HearingNorthwestern [email protected]
Lecture plan
1. Review of anatomy/physiology2. Medical treatments of vertigo3. Vestibular disorders one by one.
Important Ear Structures
The ear is an inertial navigationdevice
n Semicircular Canalsare rate sensors.
n Otoliths (utricle andsaccule) are linearaccelerometers
n Bilateral symmetrymeans redundantdesign.
Vestibular Reflexes
n VOR: Vestibulo-ocular reflex
n VSR: Vestibulospinalreflex
Vestibular symptom patterns
n Nystagmus (imbalance between ears)n Oscillopsia (low gain to one or both sides)n Motion sickness (overly sensitive to conflict
between ear/eye/somatosensation)
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Vestibular Nystagmus –result ofimbalance in VOR
1. One whole side –lateral/rotatory
2. One horizontal canal àlateral nyst.
3. One vertical canal – mixedvertical/rotatory
4. Pure vertical or torsional –usually central
How to examine for SpontaneousNystagmus
n Frenzel Goggles (best)n Ophthalmoscope (good –but
backwards)n Gaze-evoked nystagmus (use
Alexander’s law)n Sheet of white paper
(Ganzfeld – German forcomplete field)
Vestibular Nystagmus – from onehorizontal canal
Vestibular nystagmusfrom one vertical canal
Vertical/Torsion –posterior canal
Downbeating Nystagmus(Central)
Upbeating Nystagmus(Central)
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Torsional Nystagmus(Central)
Oscillopsia
Patients with complete Bilateralloss have no VOR.
Part 2
Drugs used to treat dizziness
Processes we might try to treatwith medications
n Vertigo and nystagmusn Motion sickness, emesisn Compensation for vestibular lossn Migraine
Processes we might NOT try totreat with medications
n Low VOR gain such as ototoxicityn BPPV (best managed with physical
treatments)n Malingerers (legitimate treatment facilitates
their fraud)
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Main drug categories forvertigo/nystagmus
n Anticholinergicn GABA agonistsn Everything else
Anticholinergics
n Block central and peripheral ACHn Reduce vertigo and nausea from peripheral vertigon Reduce central nystagmus (in very high doses)n Numerous interesting side-effects à
ScopolamineMuscarinic antagonist
n Scopolamine (Transderm-Scop patch)n Transderm does not require ingestion (but many
other oral GI drugs do same thing – Levsin andRobinul for example).
n Apply every 3 days to skin surfacen Withdrawal syndrome and CNS side effects limit
use
Anticholinergic side effects(Locoweed poisoning)
n Confusion (similar to druginduced Alzheimer’s)
n Dry mouth, loss of sweatingn Urinary hesitancy/stoppage.
Constipationn Blurry visionn Cardiac conduction blockn Addiction with dizziness on
withdrawall
Oxytropis lambertii
H1-antihistamines with stronganticholinergic properties
n meclizine (Antivert, Bonine)n dimenhydrinate (Dramamine)n diphenhydramine (Benadryl)
Antihistamines must cross BB barrier -- i.e. OTCfexofenidine, loratidine, cetirizine do not work fordizziness
Antihistamine side effects
n Sleepinessn Weight gain
Anticholinergic side effects• Dry mouth and eyes• Constipation• Confusion
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•12.5 TID or 25 TID. Lasts about 8 hours. Available OTC.• Limitation is sedation and anticholinergic side effects• Pregnancy: category B. May be best drug
meclizine (Antivert, Bonine)
GABA agonists(benzodiazepines)
n Modulate inhibitory transmitter GABAn Reduce vertigo and nausea from peripheral vertigon Reduce nystagmusn Sedation, addiction limit usefulnessn ? May impede compensation (strangely, no
evidence in humans for this)
Benzodiazepines
n Valium (diazepam, “Mothers little helper”)n Ativan (lorazepam)n Klonapin (clonazepam)
Dosing: beer scale1 glass of beer =
n 2 mg of diazepam (Valium)n 0.5 mg of lorazepam
(Ativan)n 0.5 mg of clonazepam
(Klonapin)
Benzodiazepines
n Should discourage benzodiazepines wheneverpractical (this does not always work).
n Benzodiazepines to discourage especially– Large doses of any benzodiazepine– Alprazolam (xanax) (high addiction)– Valium in 5mg+ doses (high addiction)
BenzodiazepinesBottom line
Extremely useful drugs for symptomsTreat dizziness and anxietyDependency is the big problem
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Diuretics
n Dyazide and Maxide (Hctz+triamterine)– Menieres
n Diamox (acetazolamide)– Menieres– Migraine– Periodic ataxia
n Lasix– Not a good idea – causes hearing loss and
hypokalemia
Drugs of unclear utility
n Beta-histine (Serc)àn Baclofen (occasionally useful)n Alternative medications
– Vertigo-HEEL (homeopathic)– Ginkgo-Biloba (very weak evidence)
Betahistine (Serc)
n FDA position is that it is a placebon Readily available from compounding pharmacies,
including Walgreensn Weak H1 agonist and H3 blocker (which results in
some Histamine agonism)n Author’s experience – Useful for motion
intolerance and Meniere’s.
•Kingma H, Bonink M, Meulenbroeks A, Konijnenberg H. Dose-dependent effectof betahistine on the vestibulo-ocular reflex: a double-blind placebo controlledstudy in patients with paroxysmal vertigo. Acta Otolaryngologica 117(5):641-6,1997
Emesis
Source: Nasa vestibular symposiumhttp://nix.nasa.gov/search.jsp?R=19740010641&qs=N%3D4294924209%2B4294946827
Vomiting is complex
Drugs used for treatment ofemesis
MOST IMPORTANT
n 5-HT3 antagonistsn Dopamine blockersn Anticholinergics (OTC)n H1 antihistaminesn Benzodiazepines
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odansetron (Zofran)5HT3 receptor antagonist
n Dose: 8 mg PO. MLT form is fast acting,regular 8mg SL is cheaper.
n Category B in pregnancy (probably safe)
Dr. Hain’s drug of choice to use prior tonauseating PT session.Generic non-MLT is available ($.35/pill)
prochlorperazine(Compazine)5, 10 and 25 mg forms,including rectal suppositories.Pregnancy -- unknown
promethazine (Phenergan).12.5, 25, 50 mg forms,including rectal suppositories12.5 BID prn oral dosetypical. Pregnancy Cat. C
Commonly used phenothiazine antiemeticsdopamine blockers
•Powerful drugs•Major side effects•Use if you have abig vomitingproblem
Commonly used phenothiazine antiemeticsdopamine blockers
Compensation
Compensation -- subtypes
n Static compensation – recovery from toneimbalance (vertigo).– Largely automatic and not likely to be modified
by drugs.n Dynamic compensation (oscillopsia) –
readjust gain.– Takes some time, modifiable by medications.
Compensation -- goal
n Facilitate compensation for static vestibularlesions or central problems. (i.e. vestibularneuritis, bilateral loss)
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Drugs that accelerate dynamiccompensation (in animals)
n Amphetaminesn Bromocriptine (Dopamine agonist)n ACTH (adreno-corticotrophic hormone)n Caffeine
Modified from Brandt, 1991
Drugs that retard dynamiccompensation in animals
n Phenobarbital (sedative, barbituate)n Dopamine antagonists (e.g. Lisuride, Thorazine)n ACTH antagonists (e.g. steroids). Steroids seem to
help in people !n Diazepam, (GABA agonist, Valium).
Modified from Brandt, 1991
Part 3
Causes of Dizziness andtheir treatment
Neuhauser et al, Neurology 65:898-904 2005
29.5% lifetime prevalence of dizziness or vertigo7% lifetime prevalence of vestibular vertigo, 1-year prevalence is5.2%
Epidemiology of DizzinessVestibular is about 1/4
Otologic (Ear) Dizziness
n BPPV (benign paroxysmalpositional vertigo) -- about50% of otologic, 20% all
n Meniere’s disease -- about20%
n Vestibular neuritis andrelated conditions (15%)
n Bilateral vestibular loss(about 1%)
n SCD and Fistula (rare butworth knowing)
Positional VertigoThe most common syndrome
nBenign ParoxysmalPositional Vertigo(BPPV) -- bed spins
n Orthostatic hypotension (dizzy upright)n Central positional nystagmus (dizzy everywhere)n Low CSF pressure syndrome (dizzy upright)
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Benign Paroxysmal PositionalVertigo (BPPV)
61 Y/O man slipped on wet floor.
LOC for 20 minutes.
In ER, unable to sit up because ofdizziness
Hallpike Maneuver: Positive
Positional VertigoDix-Hallpike Maneuver
Benign Paroxysmal PositionalVertigo (BPPV)
n 20% of all vertigo, roughly 2%population/year
n Brief and strongn Provoked by change of head positionn Definitively diagnosed by Hallpike test
BPPV Mechanism: Utricular debris migrates toposterior canal
BPPV treatment
n Medication (e.g.Antivert/zofran) – minorbenefit– May avoid vomiting by
pretreatingn Excellent response to PTn Surgery – canal plugging if
rehab fails (need morerehab after plug). Rarelydone.
Unilateral Vestibular
n Vestibular Neuritis/Labyrinthitis (common)n Meniere’s disease (unusual, 1/2000
prevalence)n Acoustic Neuroma (rare)n Vestibular paroxysmia (not sure how
common)
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Vestibular Neuritis: Case
56 y/o woman began to become dizzy after lunch.Dizziness increased over hours, and consisted of aspinning “merri-go-round” sensation, combinedwith unsteadiness.
Vomiting ensued 2 hours later, and she was broughtby family members to the ER.
Vestibular Spontaneous Nystagmusseen with video Frenzel Goggles
Vestibular Spontaneous Nystagmusrecorded on ENG(Electronystagmography)
HIT test should be positive
Vestibular Neuritis -- rxn Disturbance of unknown
cause (Viral ? Vascular)involving vestibular nerveor ganglion
n Off work -- usually 2weeks. Sometimes 2 mo.
n Symptomatic Rx(meclizine, phenergan,benzodiazepine)
n Rehab if still symptomaticafter 2 months.
n These patients can and dostill get BPPV !
Meniere’s Disease
n Prosper Meniere– Fluctuating hearing– Episodic Vertigo– Fluctuating (roaring) Tinnitus– Aural Fullness
n About 1/2000 people in populationn Chronic condition – lasts lifetime
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Etiology of Meniere’s (Dogma)n Dilation and episodic rupture of inner ear membranes
(Endolymphatic Hydrops)n As endolymph volume and pressure increases, the
utricular/saccular and Reissner’s membranes rupture,releasing potassium-rich endolymph into the perilymphcausing cochlear/vestibular paralysis
Meniere’s disease – symptoms
n Progressive hearing loss-- usually go deaf
n Episodic vertigo – out ofcommission for severaldays
n Ataxia – graduallyincreases over years
n Visual sensitivity à
Visual Sensitivity is common
n Sensory integrationdisorder – upweightvision, downweighteverything else
n Grocery store,Omnimax, Target, etc
n Typical of disorderswith intermittentvestibular problems
Otolithic Crises of Tumarkin
n Drop attacksn Go from upright to
on floor in fractionof second
n No LOCn Very dangerousn Destructive
treatment is best
Treatments of Menieres
n Medical managementnLow sodium, betahistine
n Bad rehab candidate while fluctuatingn Surgery
– Low dose gentamicin treatment works 85%– High dose gentamicin treatment (overkill)
n Rehab useful post destructive treatmentHain TC, Ostrowski T. Unsteady Influence. Menieres disease. Advancesfor directors in rehabilitation October 2007, 51-51
Acoustic Neuroma
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Acoustic Neuroma
n Rare cause ofunilateral vestibularloss
n Generally also deaf onone side
n Slowly progressive –little or no vertigo
Treatment of Acoustic Neuroma
n Watchful waiting (about 25%)n Operative removal (about 50%) – losing
groundn Gamma Knife (about 25%) – gaining
ground because effective and noninvasive.n Good rehab candidate after surgery.
Vestibular Paroxysmia (AKAmicrovascular compression)
n Irritation of vestibular nerven Quick spins, tilts, dipsn Motion sensitivityn May follow 8th nerve surgery, Gamma knife
treatment, acoustic neuroma
Clinical Diagnosis of MVC
n Quick spinsn May have
nystagmus onhyperventilation
n Response toanticonvulsant
n No rehab potential
Bilateral Vestibular Loss
A stewardess developed a toe-nail infection. Sheunderwent course of gentamicin andvancomycin. 12 days after starting therapy shedeveloped imbalance. 21 days after starting, shewas “staggering like a drunk person”. Meclizinewas prescribed. Gentamicin was stopped on day29. One year later, the patient had persistentimbalance, visual symptoms, and had notreturned to work. Hearing is normal. Sheunsuccessfully sued her doctor for malpractice.
SYMPTOMS OF BILATERALVESTIBULAR LOSS
l OSCILLOPSIA
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SYMPTOMS OF BILATERALVESTIBULAR LOSS
l ATAXIA
Bilateral Vestibular LossCauses:
n Ototoxicity !n Bilateral forms of
unilateral disorders (e.g.bilateral vestib neuritis)
n Congenital (e.g.Mondini malformation)
n idiopathic
Hain TC, Cherchi M, Yacovino DA. Bilateral Vestibular Loss. In Seminars in Neurology (ed Fife). 2013.
DIAGNOSIS IS EASY
l History of recent IV antibiotic medicationl Eyes closed tandem Romberg is positivel Dynamic illegible ‘E’ test (DIE) failed
---->
Dynamic Illegible ‘E’ test(DIE test)
n Distance vision with headstill
n Distance vision with headmoving
n Normal: 0-2 lines change.n Abnormal: 4-7 lines
change
Rapid Dolls failed
n VOR: Vestibulo-ocular reflex
LABORATORY DIAGNOSISEverything should be “dead”
l ENGl Rotatory chairl VEMP (may remain in bilateral v. neuritis)
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DIAGNOSIS Continued
l Rotatory chair confirms diagnosis butrequires cooperation
DIAGNOSIS Continued
l ENG showslittle or noresponse
Treatment Bilateral
n No medical management (other thanavoiding more damage)
n Outstanding rehab candidaten Be prepared for a deposition
Perilymph Fistula and SCD (superiorcanal dehiscence)
n Superior CanalDehiscence
Fluctuating conditions
No rehab until after surgery
Case: WSRetired plastic surgeon, with impaired hearingrelated to war injuries, found that when he wentto church, when organ was playing, certain notesmade him stagger. His otolaryngologist noted thatduring audiometry (with hearing aid in), certaintones reliably induced dizziness and a mixedvertical/torsional nystagmus. This “Tullio’sphenomenon” could be easily reproducedexperimentally. MRI scan was normal.
Tullio in SCD
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Valsalva in SCD
Superior Canal Dehiscence
n Etiology:– Congenital bone defect
(2% ?)– Trauma may
exacerbaten Treatment:
– Do nothing– Surgical
» Plug» Resurface
Diagnosis of SCD
n History of sound and pressure sensitivityn Valsalva test is easiest bedside testn Temporal bone CT scan (0.6 mm, axial
reformatted into oblique planes)n VEMP: Vestibular evoked myogenic potentials
(screen with amplitude, then do threshold)
Case: KF•After SCUBA diving, a young woman developed vertigo, auralfullness and tinnitus for 1 year.•Symptoms were worsened by tragal pressure and straining.Surgery was performed.
A large round window fistula was found andsymptoms completely resolved after a second surgery.
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Recap of diagnosesn Otologic (30-50%) – BPPV, Menieres, VN.n CNS (5-30%) – CVA, Migrainen Medical (5%-30%) Orthostatic, drugn Psychiatric (15-50%)n Undiagnosed (15%)
More details
Hain, T.C. Approach to the patientwith Dizziness and Vertigo. PracticalNeurology (Ed. Biller), Lippincott-
Raven
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